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1. Thermowell with PFA CoatingQ. I plan to order a thermowell
with PFA coating. I'd like to either order extra PFA on the process external threads. If this is not
possible then I'll order a flanged series well with PFA coating. Please explain my options.

A. Although OMEGA can provide threaded thermowells with PFA coating the amount
of coating on the threads will not prevent abrasion which will likely lead to cracks in the PFA during
insertion. Your best option is to install the thermowell in a zone where the threaded portion will not
be exposed to the contaminant such as at the top of the tank. Likewise, the female boss with a stand-off
can help further reduce the likelihood of the threads being exposed to hazardous liquid. Before installation,
be sure to wrap PFA tape around the threads as well. Also, we can coat thermowells up to 48" in length,
and supply some of the smaller flanged wells with a PFA coat on the wetted parts.

2. Surface Measurement ApplicationsQ. Are OMEGA's immersion type Omegaclad
probes such as the Quick Disconnect series as seen on page A-27 of Volume 29 Temperature Handbook good for surface
measurement applications?

A. No, any type of probe with a beaded junction and a protective
sheath (even with an exposed tip) does not provide accurate surface temperature measurements. The beaded junction will
not only pick up surface temperatures but also surrounding air temperature. One solution for surface measurement is
thin ribbon type elements as used in OMEGA's 88000 series surface probes as seen on pages A-55 through A-68 in OMEGA's
Volume 29 Temperature Handbook. Another solution is the use of non-contact infrared sensors as seen on pages A-69 and A-70.
To receive an OMEGA spec sheet on any of the above products directly to your fax machine please call 1-800-848-4271.

3. Temperature Ratings of SheathedQ. I can't understand why my .020" diameter inconel
sheathed type K probes keep failing. I am using them at 1100 degrees C which is well below the maximum published temperature
range of 1372 degrees C for type K. Could you explain why they are failing?

A. Yes, the published maximum useful temperature ranges are based on larger diameter probes which
contain larger diameter conductors. For the case in point, the .020" dia probe has wire sizes contained within the sheath
of 38 AWG (.004") dia which cannot defy the laws of physics to achieve a maximum useful temperature range except for perhaps
an extremely short time period. Refer to page H-7 of OMEGA's Volume 29 Temperature Handbook for maximum temperature ratings
of sheathed thermocouples.
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4. RTD Elements/3 Wire DesignQ. I'd like to attach lead wire to one of your RTD elements.
I am planning to use a 3 wire design so I'm assuming that I need a 4 wire element as seen on page C-23 of your Volume 29
Temperature Handbook, part number W2202. Is this correct?

A. Actually, the 4 wire W2202 is a
"dual" element. A 2 wire element such as the W2102 as offered on the same page C-23 is what is used to configure a 3
wire design. Lead wire is attached to one leg and 2 lead wires are attached to the second leg of the element. The dual
element would in fact have 6 leads attached to have a dual 3 wire design. OMEGA's Custom Engineering Dept can provide
you with pricing on the purchase of any of OMEGA's RTD elements with lead wire attached. Back to top

A. Even though the sheath and probe would be able
to withstand the temperature range the sheath material cannot stand up to actual immersion into molten metals.
In fact, most materials cannot withstand this thermal shock. Consult Custom Engineering for advice of what options
exist. Back to top

6. What color is the negative lead?A. For American thermocouples, the negative lead is red. Back to top

7. Can I bend the thermocouples?A. Yes, the bending radius should be 2 times
the probe diameter or larger. Back to top

8. What is temperature rating on the probe? (materials, type, diameterA. Various specs need to be considered when determining the temperature rating of a probe:

10. Can I get any length other than 12", 18", 24"?A. Many of the thermocouples we
sell are available in any size. Change the length in the part number to the desired length. Pricing is typically stated as a
$/in or $/foot adder. Back to top

11. How do I wire my thermocouples for electrical noisy applications?A. We recommend
sing an ungrounded thermocouple, typically low noise, in combination with twisted shielded thermocouple wire. We recommend grounding
the system at only one location to lower the possibility of generating ground loops potentials. Back to top

12. Can I twist/solder thermocouple wire to make my own thermocouples? A. This can be
done if necessary, but it is not recommended. The proper way to make a thermocouple is to weld the junction.
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13. Where is the temperature sensing done? A. The temperature sensing is done at the bead.
In the case of an Omegaclad probe, this is at the tip of the probe. Back to top

14. What is the accuracy? A. Each thermocouple type has a specific limit of error.
The accuracy will be different for the various types of thermocouples available.

15. How do I mount my thermocouple (epoxies, compr. fitting, etcA. Mounting
thermocouples is very application dependent. We sell compression fittings which can be used with probes to help with mounting.
We also sell various epoxies, heat transfer compounds, and specialized thermocouples to meet numerous applications. Consult
with our engineers regarding any specialized applications. Back to top

16. What size spools do you offer for thermocouple wire? A. The available sizes
are: 25, 50, 100, 200, 500, and 1000 foot spools. Back to top

17. Can I use copper wire to extend my thermocouples? A. No, you must
maintain the same dissimilar metals to the instrument. The B type thermocouple is the only one that can be extended
with copper wire. Back to top